Apparatus, Apparatus Purchasing, Apparatus Showcase, Pumpers

Apparatus Purchasing: Grading Engine 41

Issue 6 and Volume 18.

Bill Adams

The 2013 trade show season is underway, and apparatus pundits are rushing to print the latest and greatest innovations in the fire truck world. Recent articles heap praise on those manufacturers who can cram ten pounds of fire truck into a five-pound space. Equal admiration is bestowed on fire departments that spec multifunction apparatus to the next highest, longest, widest, heaviest, and most expensive level. It happens every year. You seldom see an article complimenting a simple straightforward single-purpose apparatus design. You never see a follow-up commentary on a rig that’s been in service for a couple of years: “Hey, Chief, how’s that design working for you? Would you change anything? Buy one like it again?”

Apparatus commentators are seldom explicit in expressing personal likes or dislikes. And, they never disagree, challenge, or take issue with a rig’s design, accoutrements, or intended function. This article will.

Readers, please take note: This is not a criticism of the manufacturer, the fire department, or how either operates. It’s irrelevant who wrote the specs, who built it, who bought it, and what it’s made out of. It’s an outsider’s personal analysis of some features of a pumper from operational and spec-writing perspectives. Maybe it’ll help the next department when writing specifications for a new rig.

Engine 41 was designed as a primary attack pumper whose sole function is to establish a water supply and put wet stuff on the red stuff. It was not designed to serve double duty as a rescue, tanker, squad, service, salvage, or ladder company. You can’t get much more basic than that. Its response area can be characterized as an older congested northeastern municipality with narrow streets, narrower alleys, and approximately 13,000 residents packed into fewer than two square miles.

Basic Design

The truck replaced an older pumper of similar size with open jump seats. The new rig, less than 29 feet long, has a short 168-inch wheelbase-only six inches longer than its predecessor. It has a six-person custom cab, 500-gallon tank, 2,000-gallon-per-minute (gpm) rated pump, preconnected truck-mounted monitor, and traditional body style with high left-side and low right-side compartments. At first glance, it looks like a ho-hum “plain Jane” vehicle. A closer look shows it’s a compact, hard-hitting, versatile, and functional piece of apparatus well suited to fulfill its intended mission.

Main Hosebed

When delivered, the main hosebed was loaded with 1,000 feet of five-inch large-diameter hose (LDH) and 1,200 feet of three-inch double-jacketed rubber-lined (DJRL) hose. A 600-foot dead load of 2½-inch DJRL was carried beneath a 2½-inch preconnect. There’s more than 150 cubic feet of space in the bed-five times the minimum required by National Fire Protection Association (NFPA) 1901, Standard for Automotive Fire Apparatus-for 2½-inch or larger fire hose. It easily accommodates the aforementioned hose plus four rear preconnects. And, it’s not full yet.

There is no issue with the quantity and size of supply line carried. That’s the department’s business. I favor large hosebed capacities. However, it could have been configured to allow a walkway to facilitate loading. A walkway in the main bed makes the troops’ lives easy. Easy is good.

Everyone likes low hosebeds. An “L” shaped tank keeps the bed less than four feet from the tailboard. And, it’s almost 40 inches deep. It looks good, but looks can be deceiving. Most firefighters have about a three-foot wing span. How easy (or hard) will it be for firefighters on top of the rig to lean or reach over the top of a couple of hosebed dividers and access the bottom of the bed? That could be problematic if you have a couple of short-armed firefighters trying to load single-stacked hose into a 40-inch-deep bed.

Engine 41
(1) At 28 feet, eight inches long with a 168-inch wheelbase, Engine 41
features a short, compact, and maneuverable design.
(Photos courtesy of CustomFIRE Apparatus unless otherwise noted.)

Crosslays

I do not favor crosslays for safety reasons. At least on Engine 41, they are at the forward part of the pump house, although a fore or aft location was not specified in either the purchaser’s or manufacturer’s specification. Buyers, beware: At least one manufacturer’s model furnishes crosslays in the aft location as standard. Be specific in location as well as capacity and dimensions. Each bed was specified to hold a single-stacked flat lay of 200 feet of 1¾-inch DJRL with a nozzle attached. The manufacturer proposed the same, specifying 3½-inch-wide by 24-inch-deep beds.

The department specified a maximum height of 74 inches from the ground to the bottom of the bed. The manufacturer offered a lower 62-inch height. Shoulder level is good. Ask the vendors what their standard dimension from ground level to the bottom of their crosslays is. Inquire if there’s an upcharge to lower it to a level where it is convenient and safe for your troops to deploy. You won’t be the first to ask. And, it may be cost-effective.

A couple of other considerations include the following: Does it matter if crosslays are wide enough so the current nozzle used can easily slide through from one side to the other (so you can pull the load from either side), and is there a chance a larger (physically sized) nozzle may be purchased in the future? Look outside the box. You’re spending a half-million dollars for a fire truck that may be around for a long, long time. Be versatile or be content with pulling hose off one side of the rig-for as long as you own it.

A flat lay of one manufacturer’s 1¾-inch hose is 3.37 inches. Again, look at the big picture. If there’s a possibility that two-inch hose may be purchased in the future, its width is 3.95 inches and it’s not going to fit. If making crosslays “a hair wider” is operationally feasible, inquire if widths can be oversized without breaking the bank. Or, you may be locked into that one size hose. Although Engine 41’s crosslays appear easy and safe to pull and shoulder load, they could be hard to repack when you are standing on the ground. The hose troughs built into the pump panel running boards could make them hazardous to stand on, then hold on with one hand and reload hose with the other. If I had my druthers, I’d eliminate the troughs and add a slide-out step on each side. It’ll make loading hose easier. Easier is better.

curb-side steamer features an operator-controlled valve recessed inside the pump house
(2) The curb-side steamer features an operator-controlled valve
recessed inside the pump house. Looping the LDH supply line around
the hydrant enables the engine to remain “close to the curb” when
making a big fire hookup.

Rear Discharges

There are dual rear 2½-inch discharges, one located each side. Purchasers should note when exact discharge locations are not specified. Some manufacturers will locate them “just beneath” the hosebed regardless of the hosebed’s height. Other manufacturers may locate them where it’s least expensive to pipe them. When large booster tanks and full-depth full-height side compartments are specified, rear discharges can end up well above a firefighter’s head-unless the purchasing specifications say otherwise. In 41’s case, with the low hosebed, rear discharges are easily accessible when you are standing on the ground. Many manufacturers have booster tanks sleeved for rear piping. Consequently, you may have the option of locating discharges where you want them. Ask. When specifying a new rig, always take into consideration the obligation to provide a “safe working environment” for the firefighters.

Purchasers seldom consider the actual flow out of rear discharges. And if they do, they probably figure a 2½-inch rear discharge flows its historical 250 gpm. Again, look down the road at the big picture. If, after delivery, it’s decided to preconnect a portable ground monitor that’ll flow 500 gpm or more, can that rear discharge supply it? A common configuration, especially in New England, is mounting a gated wye on a rear 2½-inch discharge supplying a couple of 1¾-inch preconnects. As an example, if 200 gpm is expected out of each, will the plumbing configuration supply it? Did you specify a flow rate for your rear discharges? You can.

Engine 41's pump house
(3) Engine 41’s pump house is only 44 inches wide and appears to be
user-friendly. The 2½-inch auxiliary inlet could have been located
beneath the crosslays forward of the steamer.

Engine 41’s rear discharges are three-inch-piped with three-inch valves. A similar configured piping arrangement was flow tested at over 750 gpm at 150 psi discharge pressure. That works. Buyers, beware: As an alternate to a three-inch valve, some vendors promote three-inch piping with a 2½-inch valve, saying it’s cost-effective and you’ll get just as much water. Ask exactly how much it will flow. Put the figure in your purchasing specs and see if that vendor goes into vapor lock. The actual flow to any discharge depends on the size and length of piping or flexible hose and the number and configuration of the fittings used to get water from point A to point B.

NFPA 1901, Table 16.7.2, shows “Discharge Rates by Outlet Size.” I think it’s misleading. In the Appendix, sentence A.16.7.1 says, “The flows listed for each outlet size are minimum and are for rating purposes only. If piping and valving are sufficient, much higher flows for a given outlet might be achievable.” Purchasers have the option to specify “performance” rather than a specific size pipe and valve. Let the manufacturers figure it out.

Engine 41
(4) Hosebed height is workable. Rear discharges are accessible from
ground level and can flow upward of 750 gpm each. Another 2½-inch
discharge is located at the front of the hosebed on the far left side.

Pump Panel

Despite having nine discharges, Engine 41’s pump panel does not seem cluttered or busy-it looks user-friendly. And, it’s only 44 inches wide. Caution: Some manufacturers and purchasers specify that all discharge gates and corresponding gauges on side-mounted pump panels are in a single horizontal line. It may look good, but be careful. That requirement dictates how wide the panel will have to be. You may inadvertently force the manufacturer to provide a wider panel with a larger pump house and longer wheelbase than is necessary. If a panel can be laid out that is functional and not confusing, who cares if controls and gauges are not in a straight line?

Some pump operators prefer larger 3½-inch individual line gauges than the small 2½-inch ones. They’re easier to read. Note the hinged compartment door aft of the pump house-no doubt for the pump operator’s use. Manufacturers usually allow purchasers to specify which side they want a single door hinged. In this case, the pump operator can access the compartment without walking around the door and possibly into a traffic lane. Roll-up compartments doors alleviate that problem.

Engine 41
(5) I will make no comment on color, other than it looks sharp. Looking
in a rearview mirror seeing Engine 41 behind you “lit up” with sirens
and air horn blaring could give the impression one angry hornet is
about to crawl into your trunk.

Rear Preconnects

When Engine 41 was first loaded, rear preconnected lines included two 200-foot 1¾-inch single-stacked lines connected to a wye on a rear 2½-inch discharge; a 300-foot 1¾-inch single-stacked line preconnected to a reducer on the other rear 2½-inch discharge; and 200 feet of single-stacked 2½-inch connected to a 2½-inch discharge located at the front of the hosebed. My personal preference is for various lengths of attack and backup lines along with a preconnected ground monitor. But if Engine 41’s hose load is fireground-efficient for them, the intent and objective of their purchasing committee was met and maybe we outsiders shouldn’t comment. The design and layout are flexible enough to be changed in the future if required. The bed widths for single-stacked preconnects come into play again. If your intent is to store nozzles on top of the beds, is there enough room?

Some preconnects are piped to the front of the bed. Engine 41 has one single 2½-inch preconnect piped in this manner at the extreme left of the bed. However, the actual connection is about halfway down from the top of the bed-about 20 inches. There are two concerns. If a 2½-inch preconnect is single-stacked in a five-inch-wide bed, how do you access a connection 20 inches below the tops of the hose body and divider? One alternative would be to have the pipe terminate no more than six inches below the top of the bed and have the hosebed divider bias-cut at the front of the bed so you can get your hands and a spanner on the outlet. Secondly, having preconnects piped to the front of the bed pretty much mandates where those preconnects will be forever located. There is little flexibility down the road to change hose loads.

engine from Carlisle, Massachusetts
(6) This engine from Carlisle, Massachusetts, features the common
New England practice of using a gated wye on a rear discharge to run
two preconnects. Low-mounted rear LDH discharge and suction
connections may be desirable.
(Photo by author.)

2½-Inch Auxiliary Suction

Exercise caution if a vendor tells you the NFPA requires a 2½-inch gated intake. The vendor is wrong. NFPA 1901 sentence 16.6.3 states, “At least one valved intake shall be provided that is controlled from the operator’s position.” Sentence 16.6.3.2 says it has to be at least 2½ inches. If you want it to be a six-inch intake, so be it. The NFPA does not say the intake physically has to be on the operator’s panel-just that it’s controlled from there. If you are adamant that a 2½-inch inlet must be at the operator’s panel, consider locating it under the crosslays away from the tank fill, tank suction, and governor (or relief valve) controls. In Engine 41’s case, it is located where the pump operator will probably be standing. Ask if you have the option to pick the location. The pump operators will appreciate it.

Gated Steamer Inlet

Engine 41 does not have a gated front suction. Its primary function is initial attack, probably forward laying when supplying its own water. It doesn’t drop attack lines and reverse lay looking for a plug. The department has a pump-operator-controlled valve on the curb-side steamer to accommodate LDH and make big fire hookups. It’s not at the pump operator’s position. My first preference is for a rear gated LDH suction. That’s where you break your supply line to make a connection. You can throw excess hose off to one side and possibly keep a traffic lane open for incoming apparatus.

engine 41
(7) A 2½-inch and three 1¾-inch preconnects were initially loaded in
the main bed when delivered. In addition to the rear 2½-inch discharge
located in the front of the hosebed, the two three-inch rear discharges
can flow more than 750 gpm each. Consequently, higher flow
preconnects can be easily added at a later date without piping
modifications. The three- and five-inch supply line beds appear they
could be loaded in two tiers, allowing a walkway to facilitate hose
loading.
(Photo by Jay Abel.)

I also like gated front suctions that could do triple duty: making a big fire hookup, taking in a second LDH supply line, and meeting the NFPA’s requirement for a gated suction. The downside is a longer rig and an increased wall-to-wall turning radius-probably a concern in 41’s congested response area. And, it’s expensive.

I agree with the NFPA that discharges and inlets do not belong on the pump operator’s panel. Take note of sentence A.16.9.1 in NFPA 1901’s appendix. It states, “Ideally, having no intake or discharge connections at the operator’s position would simplify and improve safety for the operator.” It goes on, “If complete removal of these connections is impractical, the reduction and careful placement of these connections, with operator safety in mind, would improve the situation considerably.” It must have put that in there for a reason.

Engine 41 appears to be a well-laid-out pumper, more than capable of performing the tasks of a basic engine company. It’s short, maneuverable, and packs a good punch-it looks effective. I like it.

BILL ADAMS is a former fire apparatus salesman, a past chief, and an active member of the East Rochester (NY) Fire Department. He has more than 45 years of experience in the volunteer fire service.